Perhaps the best place to start is to underline the word, "mass." In other words, mass media is aiming at as many people as possible. So, selectivity of population is not the point.

When we begin to understand this point, then we can appreciate that programming in mass media will target what will gain more viewers and sustain their loyalty. One of the strategies to achieve this is to give what people want. And one way of doing this is to appeal to their needs, even biological needs. For example, it is clear that "sex" sells. This is why it is ubiquitous in mass media. This type of mass media is aiming at our biological desires.